49 research outputs found

    Variación morfológica de Cedrela odorata (Meliaceae): contraste entre poblaciones naturales y con manejo

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    Background and Aims: Cedrela odorata (Spanish cedar) is a tropical tree native to America with an important international trade market. In this study, the morphological variation of C. odorata was compared among three conditions: logging, plantations, and natural populations, with the objective to evaluate the current condition of managed populations after harvesting and in plantations, in contrast to relatively well-preserved populations.Methods: Two sites were chosen for each condition. The population density and four morphological attributes were measured: diameter at breast height, height, angle of branch insertion and crown form. A multivariate approach was used to compare the morphological variation among conditions (generalized discriminant factors analysis) and determine total variation distributed among size classes (cluster analysis), as well as assignment of these classes to each condition (canonical correspondence analysis).Key results: Four significantly different size classes were identified among all populations with specific association to condition. Strongest correlations were between highest trees with natural populations and small trees with plantations. Forest management, including harvesting and plantation conditions, reduced the phenotypical variation and modified the dasometrical attributes of C. odorata. The logging of the better shaped phenotypes increased the smaller size trees frequency compared to commercial size individuals, and changed the forest composition favoring small categories.Conclusions: The forest exploitation generates homogenization in median height-class and the plantation in lower height-class. In both cases, the harvestable trees are scarce, even after 20 years of management; and they are non-existent in plantations of 15 years. These results suggest that the removal of the highest trees, as well as forest plantations, are not being effective to wood production since they do not reach commercial sizes in the time of recovery or projected growth. Antecedentes y Objetivos: Cedrela odorata (cedro) es un árbol tropical nativo de América con un importante mercado internacional. En el presente estudio, se comparó la variación morfológica de C. odorata en tres condiciones: bajo extracción, plantaciones y poblaciones naturales, con el objetivo de evaluar la condición actual de las poblaciones después de la extracción y en plantaciones, en contraste con las poblaciones relativamente bien conservadas.Métodos: Se eligieron dos sitios para cada condición. Se midió la densidad poblacional y cuatro atributos morfológicos: diámetro a la altura del pecho, altura, ángulo de inserción de las ramas y forma de la copa. Se usó una aproximación multivariada para comparar la variación morfológica entre condiciones (análisis de funciones discriminantes generalizado), y para determinar la variación total distribuida entre clases de talla (análisis de agrupamiento); además, se asignaron esas clases a cada condición (análisis de correspondencias canónicas).Resultados clave: En todas las poblaciones fueron identificadas cuatro clases de talla significativamente distintas. Las correlaciones más fuertes fueron entre los árboles más grandes con las poblaciones naturales y los más pequeños con las plantaciones. El manejo forestal, que incluye las condiciones bajo extracción y las plantaciones, redujo la variación fenotípica y modificó los atributos dasométricos de C. odorata. La extracción de fenotipos mejor conformados incrementa la frecuencia de árboles de menor talla, respecto a individuos de tamaño comercial, y cambia la composición del bosque favoreciendo las categorías pequeñas.Conclusiones: El aprovechamiento forestal genera homogenización en clases de talla mediana, en cambio, en las plantaciones se homogenizan las clases de menor tamaño. En ambos casos, los árboles cosechables son escasos, aún después de 20 años de manejo, y no existen en cultivos de 15 años. Estos resultados sugieren que la remoción de los árboles más grandes, así como las plantaciones forestales, no son efectivas para la producción de madera puesto que no se encontraron árboles de tallas comerciales en el tiempo de recuperación o crecimiento proyectado

    Nanosystems as Quorum Quenchers Targeting Foodborne Pathogens: Understanding the Inhibition Mechanisms and Their Docking Predictions

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    Food poisoning is one of the main problems affecting public health. Bacterial adhesion on surfaces has been documented for decades, and it is known that biofilm-forming bacteria are much more resistant than planktonic cells. Typically, nanosystems are studied regarding their antimicrobial activity (i.e., pathogenic bacteria such as Campylobacter, Salmonella, Listeria monocytogenes, Escherichia coli O157:H7, Staphylococcus aureus, Clostridium perfringens, Bacillus cereus, and Yersinia enterocolitica), but not for antibiofilm activity and their associated genes. Some studies established protein-ligand prediction concerning quorum sensing suppression, commonly called quorum quenching. This chapter focuses on nanosystems or functionalized nanomaterials that have demonstrated antibiofilm or quorum quenching activity and, thus, establishes perspectives in modeling specific nanosystems to eradicate biofilms produced by foodborne pathogens

    Lo tangible e intangible del diseño

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    1 archivo PDF (366 páginas)"El Departamento de Evaluación del Diseño, en el Tiempo de la División de Ciencias y Artes para el Diseño de la Universidad Autónoma Metropolitana, Azcapotzalco, publica este libro colectivo, donde se aborda la discusión y el análisis sobre "Lo tangible e intangible del diseño". Este libro tiene como finalidad el profundizar en distintas posiciones teóricas, metodológicas y empíricas, donde un grupo interdisciplinario de profesores investigadores del Departamento de Evaluación, desde la arquitectura, los estudios urbanos, la educación, la historia, la semiótica, el diseño de la comunicación gráfica y el industrial; buscan convergencias y discuten divergencias que puedan generar servir como referentes intelectuales y teóricos, en el diseño. Este libro es resultado del Cuarto Coloquio Departamental: Lo tangible e Intangible del Diseño. Evaluación de Objetos, Espacios, Mensajes, realizado durante el mes de septiembre del año 2004, el cual se constituyó como un espacio para el intercambio de experiencias académicas y profesionales, desde una perspectiva interdisciplinaria, centrada en la reflexión y la discusión sobre la manera de cómo se puede analizar, definir y evaluar, lo tangible y lo intangible en el diseño"

    Epigenetic mechanisms of particulate matter exposure: air pollution and hazards on human health

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    Environmental pollution nowadays has not only a direct correlation with human health changes but a direct social impact. Epidemiological studies have evidenced the increased damage to human health on a daily basis because of damage to the ecological niche. Rapid urban growth and industrialized societies importantly compromise air quality, which can be assessed by a notable accumulation of air pollutants in both the gas and the particle phases. Of them, particulate matter (PM) represents a highly complex mixture of organic and inorganic compounds of the most variable size, composition, and origin. PM being one of the most complex environmental pollutants, its accumulation also varies in a temporal and spatial manner, which challenges current analytical techniques used to investigate PM interactions. Nevertheless, the characterization of the chemical composition of PM is a reliable indicator of the composition of the atmosphere, the quality of breathed air in urbanized societies, industrial zones and consequently gives support for pertinent measures to avoid serious health damage. Epigenomic damage is one of the most promising biological mechanisms of air pollution-derived carcinogenesis. Therefore, this review aims to highlight the implication of PM exposure in diverse molecular mechanisms driving human diseases by altered epigenetic regulation. The presented findings in the context of pan-organic cancer, fibrosis, neurodegeneration and metabolic diseases may provide valuable insights into the toxicity effects of PM components at the epigenomic level and may serve as biomarkers of early detection for novel targeted therapies

    Database of spatial distribution of non indigenous species in Spanish marine waters

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    Research in marine Spanish waters are focused on several actions to achieve an effectively management on protected areas, with the active participation of the stakeholders and research as basic tools for decision-making. Among these actions, there is one about the knowledge and control on NIS. One of its objectives is the creation of NIS factsheets, which are going to be added to the National Marine Biodiversity Geographical System (GIS) providing complementary information about taxonomic classification, common names, taxonomic synonyms, species illustrations, identification morphological characters, habitat in the native and introduced regions, biological and ecological traits, GenBank DNA sequences, world distribution, first record and evolution in the introduced areas, likely pathways of introduction, effects in the habitats and interaction with native species, and potential management measures to apply. The database will also provide data for (1) the European online platforms, (2) the environmental assessment for the Descriptor 2 (D2-NIS) of the EU Marine Strategy Framework Directive (MSFD), as well as (3) supporting decisions made by stakeholders. It is the result of extensive collaboration among scientist, manager’s and citizen science in the Spanish North-Atlantic, South-Atlantic, Gibraltar Strait-Alboran, Levantine-Balearic and Canary Islands marine divisions, providing an updated overview of the spatial distribution of relevant extended and invasive NIS of recent and established NIS introduced by maritime transport and aquaculture pathways, as well as on cryptogenic or native species in expansion due to the climatic water warming trend

    The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

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    Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

    MAREJADAS RURALES Y LUCHA POR LA VIDA, VOL. I:CONSTRUCCIÓN SOCIOCULTURAL Y ECONÓMICA DEL CAMPO.

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    Este volumen incluye trabajos que abordan temáticas que demuestran que el campo es una construcción sociocultural, por lo tanto, el medio rural es diferenciado y está en constante cambio y adaptación a los procesos globales y locales. Son 19 trabajos divididos en dos secciones, la primera, denominada Nuevas dinámicas sociales, económicas y culturales en el medio rural, está compuesta por 8 capítulos, en esta sección se incluyen aquellos trabajos que analizan de manera concreta los cambios perceptibles en las relaciones rurales y en las actividades económicas; procesos como desagrarización y nuevas actividades económicas son abordados aquí, así como propuestas metodológicas para el estudio de lo rural considerando los cambios y adaptaciones que se registran en los territorios. La segunda sección, Resistencias y alternativas al modelo neoliberal en la producción agrícola y alimentaria, está integrada por 11 trabajos que abordan las diversas formas en que los campesinos y productores agrícolas resisten y se adaptan a los cambios globales y a las modificaciones de política pública, desde los mercados alternativos hasta la producción de nuevos cultivos que generan un mercado nuevo a su producción, hasta las resistencias y defensa de la milpa, las reflexiones que nos ofrecen dan idea de la diversidad de formas en que la vida campesina se mantiene a pesar de todos los embates.INSTITUTO DE CIENCIAS AGROPECUARIAS Y RURALES (ICAR), UNIVERSIDAD DE GUADALAJARA, EL COLEGIO DE MICHOACÁN A.C., CUCOSTA SUR GRANA, FACULTAD DE ESTUDIOS SUPERIORES ACATLÁN-UNAM, ECOSU

    Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

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    Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe
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